1. Field of the Invention
This invention relates generally to brackets for joining the legs of a saw horse or similar apparatus and more particularly to such a bracket formed from sheet metal and providing dual parallel interlocking faces.
2. Description of Related Art
The following art defines the present state of this field:
Rice, U.S. Pat. No. 936,945 describes a device comprising oppositely arranged substantially rectangular plates provided at each end with a flange connected to the plate by a triangular portion, whose apex is upward, whereby to set off and incline the plate with respect to the flanges, said flanges having at each end an ear, the lower ears of the oppositely arranged plates being integral with each other, and said plates, flanges and ears having openings therethrough.
Rebensdorf, U.S. Pat. No. 2,825,606 describes a device for use in assembling, erecting and temporarily coupling horizontal and vertical timbers such as are used, for example, in constructing a knockdown trestle; a bracket comprising a pair of spaced parallel open-ended sleeves adapted for telescoping reception and retention of the end portions of a pair of horizontal beam-forming timbers, means securing said sleeves to each other, and a pair of companion open-ended socket members opposed to each other and affixed at right angles to the outer end portions of their respective sleeves and likewise adapted for telescoping reception and retention of vertical leg-forming timbers.
Tucker, U.S. Pat. No. 2,874,004 describes a portable trestle comprising a pair of legs adapted to support a horizontal member, a bracket at the upper end of each leg and having a head for bearing against the underside of the member, an upper flexible element having connection with the brackets and adapted to overlie the member, and a lower flexible element for connecting the medial portions of the legs for holding the upper element and brackets in engagement with the member when said legs are swung toward each other.
Mitchell, U.S. Pat. No. 3,012,627 describes a ladder iron unit comprising a hollow rectangular body having a rectangular planar rear wall, first and second opposing end walls and a top wall, said first and second end walls and said top wall disposed entirely on one side of said rear wall and: oriented normal thereto, said end walls secured to opposite parallel edges of said rear wall in opposed rotation, said top wall disposed normal to said rear wall and secured along one side to said rear wall and along each of its ends to said end walls; said top wall extending laterally from said rear wall beyond said end walls and terminating in a lip portion extending normal to the remainder of said-top—wall in a direction toward said end walls; one of said end walls formed with a plurality of threaded openings therethrough; a threaded thumb-screw engaged in each of said threaded openings and extending therethrough; and a hinge plate portion joined to said rear wall along the edge of said rear wall corresponding to the location of said top wall and extending on the side of said top wall opposite from said rear wall, said hinge plate disposed with its rear face coplanar with the rear face-of-said rear well, said hinge plats extending laterally beyond each end of said body, said hinge plate formed with two spaced hinge bolt openings therethrough disposed adjacent opposite ends of said hinge plate; said tear wall formed with a plurality of openings therethrough, each of said openings in said rear wait spaced from one of said openings in said hinge plate the same distance as the space between said openings in said hinge plate; one of said, end walls extending downwardly beyond said rear wall and terminating in an outwardly curved bifurcated hook portion, said iron sized and adapted to engage the end of a ladder sidepiece whereby said top wall will extend over the end of said sidepiece and said iron maybe clamped on said sidepiece by tightening said thumb-screws.
Huntington, U.S. Pat. No. 3,691,526 describes a traffic barricade-type structure constructed entirely of polymeric material such as high impact styrene and vinyl and including a pair of spaced A-shaped elongated strip supports with a pair of generally horizontal spaced elongated strips disposed on each side of the A-shaped supports. These supports are hinged at the apex thereof by resilient straps and the spacing between the legs of the supports is limited by transversely disposed resilient straps which may be temporarily uncoupled to allow the supports to be reversed to expose different safety indicia.
Brow, U.S. Pat. No. 5,078,352 describes a foldable sawhorse comprising a two-by-four wooden work member supported in a sheet metal channel near each of its ends. The channels are supported by two tubular leg assemblies pivotally attached to the channels. The pivotal attachments comprise an eye extending from the bottom of each channel and passing through holes in the walls of the legs of the leg assemblies. Each leg assembly comprises two legs and a base; the legs are flattened in cross-section at one of their ends and welded to the base near its ends with the long dimension of the flattened section parallel to the axis of the base. The center portions of the bases are raised a distance equal to about ⅛ the lengths of the bases and are interconnected by a strap which determines the angles between the legs when the sawhorse is unfolded. A lock is provided to prevent inadvertent folding of the leg assemblies toward each other. It comprises a flat rectangular part with two L-shaped slots located such that one leg of each slot is close and parallel to the ends of the part and the other legs extend toward each other and are close and parallel to the bottom edge of the part. The part is attached by collared fasteners to two of the legs near their pivoted connection to a channel such that when the leg assemblies are unfolded the lock part is allowed to move so that the collars of the fasteners are in the slot portions parallel to the ends of the part, preventing the sawhorse from being folded until the lock part is manually lifted to allow the fasteners to move toward each other in the slot portions parallel to the bottom edge of the lock part.
Short, V et al., U.S. Pat. No. 5,950,392 describes a truss element of a structure that is prefabricated, but hinged so that trusses may be reduced in size for transportation and storage. The hinge is made up of a sheet of flexible material, which is affixed to elements of the truss by press fit plates. This press fit hinge can be installed on the truss simultaneously with the other press fit plates used to construct the truss, thereby dramatically reducing the number of steps required to construct the truss while still providing the desired feature of the hinge.
Dirk, II, U.S. Pat. No. 6,142,256 describes a folding sawhorse that is formed from a pair of substantially identical rectangular frames. The frames are constructed from four substantially identical wooden members via lap joints to make a smooth construction. The frames are also pivotally joined together by a pair of hinges fixedly coupled to top portions thereof. A flexible member or chain extends between the frames, but is displaced from the hinges. The hinges allow for pivotal movement of the frames, while the chain limits the range of pivotal movement.
Krajec, U.S. Pat. No. 6,564,903 describes a sawhorse that is constructed with brackets allowing the legs of the sawhorse to fold into a compact unit by having the legs interleave when folded. The legs pivot about a plane that is canted to allow each leg to rotate without interfering with any other leg. The length of the legs is not restricted in any fashion. The legs may also be locked in the extended or service position as well as the closed position. The bracket may be constructed of as few as two unique parts, and a pair may be nested together for compact shipping, storage, and display on a store shelf.
Our prior art search with abstracts described above teaches: a timber coupling and trestle-erecting bracket, a support structure, a socket piece for studding, folding sawhorses, a hinged truss, a collapsible sawhorse bracket with interleaving legs, portable trestles, and a safety device for directing traffic, but does not teach a one piece sheet metal stamped and folded bracket or its use in preparing low cost hinges for a collapsible saw horse. The present invention fulfills these needs and provides further related advantages as described in the following summary.